WASHINGTON  Copycats, crackpots or office cutups who fake anthrax scares or other acts of terror would be charged with a new federal crime under legislation proposed in the Senate.

Thousands of false alarms since the Sept. 11 hijackings have strained law-enforcement agencies already working overtime to investigate threats.

The Senate bill would punish people who deliberately threaten or falsely report a terrorist attack with up to five years in prison, fines and restitution for the cost of responding to the hoaxes.

Sen. Mike DeWine, R-Ohio, blamed the hoaxes for adding to the panic over terrorism.

They are taxing our already strained emergency management and public health resources, which are vital to protect our national security, said the senator, who sponsored the bill with Sen. Charles Schumer, D-N.Y.

Federal prosecutors have issued at least 11 indictments or complaints related to false threats or hoaxes since Sept. 11 under existing anti-terrorism laws.

Some of the hoaxes are simply bizarre jokes gone bad, but others have a more sinister edge.

Abortion-rights groups reported last week that more than 200 clinics and organizations received FedEx packages containing a powdery substance. Some had letters claiming the powder was anthrax.

Since the attacks, the FBI has responded to more than 7,000 letters feared to have contained anthrax, 950 incidents involving weapons, and more than 29,000 calls about suspicious packages.